Near Earth Objects

The space between the planets in the universe is not empty. There are many particles or objects of different sizes that may range from a smaller dust particle to a large size asteroids or comets. The number of small particles called meteors is greater than the other objects or particles. Meteors are also called as shooting stars. While on the other hand the number of large size asteroids or comets is very small so there are scarce chances of any damage to our earth from these asteroids. The larger asteroids, ranging from 10 km to 20 km in size, may be the cause of damage to our planet. The impact of such asteroids is very dangerous and these asteroids may destroy the life over earth. A risk summary of the some of the near earth objects is shown below in the table.

Table: Recently Observed Objects within Past 60 Days

Object Designation

Torino Scale (Max)

Palermo Scale (Max)

Palermo Scale (Cummulative)

Impact Probability (Cummulative)

Vimpact

Vinfinity

H

(Mag)

Diameter

Mass

Energy

Potentail Impacts

2010NY65

0

-4.70

-4.53

3.0e-08

22.28

19.29

20.9

0.223

1.5e+10kg

9.1e+02 MT

22

2010MY112

0

-5.35

-4.80

3.2e-08

26.30

23.82

20.7

0.250

2.0e+10kg

1.7e+03MT

34

2010LV108

0

-5.17

-4.88

7.0e-07

14.50

9.28

22.4

0.111

2.0e+09kg

5.0e+09MT

17

2010MU112

0

-5.07

-4.90

3.9e-08

31.20

29.15

21.0

0220

1.4e+10kg

1.6e+03MT

5

2010JH110

0

-5.26

-5.11

6.8e-05

13.76

8.08

26.3

0.019

8.9e+06kg

2.0e-01MT

3

2010MZ112

0

-6.64

-5.60

2.0e-06

11.37

2.09

25.0

0.036

9.3e+07kg

1.5e+00MT

177

2010NH

0

-6.42

-6.36

1.7e-06

15.17

10.29

25.7

0.025

2.1e+07kg

5.7e+04MT

3

2010NN

0

-7.01

-6.42

2.7e-05

13.55

7.72

28.3

0.007

5.2e+05kg

1.1e-02MT

63

2010MA113

0

-7.14

-7.07

5.4e-09

12.60

5.87

21.9

0.140

3.9e+09kg

7.3e+01MT

2

2010LD64

0

-7.37

-7.28

1.0e-07

15.15

10.26

25.4

0.028

3.0e+07kg

8.2e+01MT

9

2010LG61

0

-9.66

-8.88

1.1e-08

11.19

0.95

26.7

0.016

7.7e+06kg

1.2e+01MT

9

The above table is a summary of the hazards of the designated object or its impact on the earth. Some of the details of the technical points are as under:

Vimpact = It is velocity of object at atmospheric entry

Vinfinity = It is also called as hyperbolic access velocity. It is the relative velocity of the object at atmospheric entry and the acceleration caused by the earth gravity field is neglected.

The earth escape velocity can be calculated as:

Vinfinity2 = Vimpact2 - Vescape2, where Vescape = ~11.2 km/s

H= It is the absolute magnitude which is used to measure the intrinsic brightness of

object.

Diameter= It is an estimate on the basis of absolute magnitude of the object and it is

assumed as a uniformed spherical body with visual albedo pv =0.154

Mass= It is also based on estimate and it is asumed that a uniform spherical body with

with the computed diameter and a mass density of 2.6g/cm3

Energy = The KE at impact: 0.5 * Mass * Vimpact2. The energy is measured in

megatons of TNT.

In the research the larger asteriods or comets are of major concern, an asteroid or comets of range of 1 to some km can prove dangerous or lethal for the very existance of life on earth. Such asteroids are too much bigger in size and can be seen easily using powerfull telescopes. The near earth objects are monitored on regulary basis and their diameters and orbital tracks are calculated and most of the asteroids or comets are not harmful to our planet. Scientists and engineers have found most of the asteroids or comets or near earth objects around the earth and the remaining will be found at later stages in the research. The projectiles which may be harmful are of the size of a sand particle or in the size of a pea. These meteroids produce very bright meteors which can be seen easily by the human beings. Such small sized meteroids can destroy our technical inventions like space shuttles, satellites, and all commodities in the space because they would blast if an asteriod or comets strikes them though the possibility of strike is very rare.

The frequency of impacts of such meteors can be calculated easily be the astronomers. Using the frequency of the impacts the astronomers can tell the ways to save the space property on the basis of the predictions given by them. Like diameter of an asteroid or comets will help to find out the size of the object and then also helpful to find out the striking power with which the object will strike to another object and astronomers will have to calculate these things very earlier.

The meteoroids of larger size are of greater concern than the meteoroids of smaller size. The impact rates and the hazards of such meteoroids will vary enormously than the smaller one. These objects show some characteristis which are important to expose here i.e. their explosion if anywhere may cause a greater disaster or problem, most of the asteroids or meteoroids are not visible in the telescopes so it is impossible to detect them immediately. In the last the very nature and charactersitics of these objects are not standardized. There are many doubts and uncertainties about these objects with varying sizes and hazard impacts. If the common people are unaware with the hazards of these objects then on the other hand the people who are highly involved is such matters like military personal are also unfamiliar about the impact frequencie of these meteoroids. The impact of a hazard is dependant upon the very size of an object. Even a meteoroid of smaller size which may be in some meters can be the cause of number of deaths which may be the equivalent of number of annual of hazards on a continent.

There are many examples of near earth object hazards or impacts on earth. One of the important and noteworthy examples is of Tsunami Generator. The very cause of a tsunami generator is earhquack but for better understanding in the research the cause of tsunami is relted with the strike of an asteroid or meteoroid with ocean. The very impact or hazard of it can be explained in way that consider an object of huge size strikes our earth with a speed far more greater than the speed which we have in our perceptions when we compare it with our real life like the speed of a jet aeroplane is consider the faster one but in case of an asteroid it may be hundred or thousands time greater than the speed which we observe on this earth. As probability is the very essence of this research so probably the very meteoroid would not strike the land rather it is possible it may explode somewhere in the ocean with an energy of hundreds of MT or TNT. So anything very close to the impact of that meteoroid would be destroyed. But the most notable thing would be the Tsunami or the tidal wave which would be generated in the result of the strike or explosion of that object in the ocean. So the impact on the nearby areas may vary according to the proximity. If an area would be closer to the impact factor then the consequences of the tsunami would be severe than in those area which are not quite near to the impact point. The very height of resulting wave or tide of the tsuanmi will be in meters. An uncertainty prevails among researchers about the impact of tsunami (Ward & Asphaug, 2000; Hills & Mader, 1997). The very impact of the height of the tide of tsumani may vary according to the size and speed of the meteoroid. And there may be the possibility of numerous waves or tides that may hit a coastline.

The possibility of such tsunami is based on the strike of an asteroid or meteoroid in ocean so the happening of this accident or hazard is only possible in those areas or countries which are touching the coastline and all other countries which are far behind the coastline will remain safe from such an accident. There are rare chances to discover the very generation of such impacts like tsunami which are caused by the near earth objects. The very mitigation efforts, in order to cope with such accidents, must be taken well before accident happening. The governments or the bodies in the different countries must try to prohibit the development activities within the hundred kilomters of the coastaline and they must convince the people that not to live in such an area which is dangerous for their very existence and then in the last forcefully evacute them from the danger zone.